Up until the late 1960s all cockles were collected by hand raking.Following
a decline in the hand-raking fishery the hydraulic cockle dredge was developed by the White Fish Authority. This proved successful although damage rates to cockles were initially high.The development of new harvesting systems saw the introduction of the solids handling pump in the early 1990s, this
combined with other modifications to dredge design has meantthat catch smash
rates of around 20% in the 1970s have now mostly been reduced to below 5%.

As the industry modernised,
new vessels were built with even greater catching capacity, which in turn triggered the need for improved monitoring and management
of the fishery.In 1991 new European Shellfish Hygiene legislation came into
operation, which proceeded to open up the fishery and put increased pressure upon stocks, to a level that could be detrimental
to its sustainable long term production.To counteract this K&E SFC worked
with the local cockle industry to develop the present day level of fishery management.

Management
of the cockle stocks

To help develop and protect the cockles within the district a series of byelaws were passed which laid down the conditions
by which people could remove cockles in a way that was deemed sustainable.To
this end there are byelaws limiting:

·maximum vessel size

·engine power

·dredge size

·minimum cockle size

·maximum damage rate

·closure of beds/closed
season

·fishing times and quantities
landed

·additional fishing
permit requirements

The Thames Estuary Cockle Fishery Regulating Order came into operation in 1994 and covers the major section of the
fishery (picture below), only 14 vessels are licensed to fish for cockles within this area.An important part of management has been policy that closes beds to commercial exploitation once stock levels drop
below set limits.

In addition to local vessels, up to 20 visiting vessels from the Wash and West coast ports have worked the outer areas
not covered by the Regulating Order.Skippers are required to return catch data
showing area fished, quantity taken and fishing time.

Kent and Essex Sea Fisheries District - Cockle Harvesting Areas

This chart is for illustrative purposes only, for exact details of fishing areas contact K&E SFC

These grounds are within the area covered by the Thames Estuary Cockle Fishery Order 1994.A licence granted under the Order is required in addition to a permit issued under Byelaws.

1Marsh End and Chapman Sands

2East of Pier

3West of Shoebury Boom

4East of Shoebury Boom

5aSouth Maplin

5bMid Maplin

6North Maplin and Foulness Sand

8 East Barrow and Maplin Spit

9West Barrow

11East Cant, Middle and Red Sand

12Sunk Sand

13West Cant and Scrapsgate

15North Margate Sand and Pan Sand

16Shingles and Long Sand

These beds are outside the area of the Thames Estuary Cockle Fishery Order. Cockles taken from within these areas are subject
to K&ESFC Byelaws.

1aInner Estuary

7Buxey and Dengie Sands

10Pollard, Columbine and Whitstable

14South Margate Sands

17SouthKentCoast to Dungeness

18Gunfleet Sand

19Blackwater Estuary

20Wallet and NorthEssexCoast

Assessing cockle stocks

It is assumed that environmental conditions are by far the largest factor governing recruitment.Due to the relatively short life cycle of cockles due to natural mortality (mean natural
mortality rates have been calculated as 64% during their first winter, 28% during their second winter and third winter) there
are few cockles above 5 years old found on the exposed grounds, even in areas that have not been fished.This makes long-term management difficult with high dependence on continued new recruitment into the fishery.For this reason it is vital, for the sustainable management of the fishery, to assess
the spawning stock on an annual basis.

The management of the cockle stocks aims to regulate exploitation of the stock and maintain a core spawning
biomass of adult cockles.To achieve this cockle socks are surveyed twice a year
to assess their density and size distribution.Annual Total Allowable Catch (TAC)
limits are set following completion of Spring surveys carried out during April. These assess remaining stock on the major
beds and this information is combined with other stock data resulting in a TAC set at a maximum level of 33% of adult stock.

Cockle surveys on the areas Maplin and Foulness Sands have been carried out for nearly 20 years.Initially they were carried out using trials bikes, however in the last few years quad bikes have proved
far easier to use in this environment.Quadrate samples are taken along the sands
every quarter of a minute of latitude and longitude, and the number and age of the cockles at each location is recorded.The mean weight of cockles for each age group is also calculated for each management
area.In conjunction to this the patrol vessel also uses a day grab to sample
cockles in other areas within the Regulating Order.